In general, a magnesium alloy has the lowest density and the lightest weight and also has high tensile strength among practically utilized alloys. Thus, magnesium alloy is increasingly applied to a casing of an electric product, a wheel, a suspension, and parts around an engine of an automobile, and the like.
Particularly, high mechanical properties are required for parts used in relation to automobiles. Thus, as a magnesium alloy to which elements such as Gd and Zn are added, a material of a specific form is manufactured by a single roll method and a rapid solidification method (for example, refer to Patent Document 1 and Patent Document 2).
However, regarding the magnesium alloy described above, although high mechanical properties are obtained with a specific manufacturing method, there is a problem that special facilities are required in order to realize the specific manufacturing method and moreover, productivity is low. Furthermore, there is a problem that applicable members are limited.
Conventionally, there is a proposed technique that in a case of manufacturing a magnesium alloy, even when highly-productive normal melting and casting and then plastic working (extrusion) are performed without using the special facilities or processes as described in Patent Document 1 and Patent Document 2 above, practically useful mechanical properties are obtained (for example, refer to Patent Document 3).